Rule asssembly with reduced housing size

ABSTRACT

A retractable rule assembly includes a housing assembly and a reel rotatably mounted in the housing assembly. An elongated blade formed of a ribbon of metal having one end connected to the reel is constructed and arranged with respect to the housing assembly to extend from a position tangential to the reel outwardly through a spaced opening in the housing assembly. The blade has a hook member on the free end thereof. The hook member includes a hook portion and a mounting portion extending generally perpendicular from the hook portion. The mounting portion is connected with the free end of the blade for limited relative movement along the blade in an amount generally equal to thickness of the hook portion. A coil spring formed of a ribbon of metal has a construction and arrangement between the housing assembly and the reel to rotate the reel in the housing assembly in a direction to wind up the elongated blade when extending outwardly of the housing assembly opening in a normal concavo-convex cross-sectional configuration onto the reel in an abutting volute coil formation in a flattened cross-sectional configuration. A blade holding assembly is constructed and arranged to be manually actuated to hold the blade in any position of extension outwardly of the housing assembly opening and to release the blade from any position in which it is held. The metal ribbon of the spring has a width which is 95%-120% of the width of the metal ribbon of the blade.

BACKGROUND OF THE INVENTION

Spring retractable rule assemblies have been available commercially formany years. Among the most desirable characteristics commercial ruleassemblies can possess is a relatively long total blade length and arelatively compact housing that is of a size and shape, for example,that can easily and comfortably fit in a hand of person using theassembly or that can easily be carried in a pocket or on a belt.

A typical retractable tape rule assembly includes an elongated thinmetal rule blade that is mounted on a reel rotatably disposed within ahousing assembly. The rule blade is retracted into the housing assemblyfor storage by coiling it about the reel. In a spring retractable typerule assembly, a coil spring is mounted inside the reel between the reeland a spindle of the housing assembly to provide spring poweredrewinding of the blade.

A typical coil spring has a flat ribbon-like metal structure. Springpower is directly related to spring width, thickness and length so thatspring power can be increased by increasing any combination of thesethree dimensions. Increasing spring thickness and/or length, however,requires making the height and length of the housing assembly (i.e., theside dimensions or “footprint”) larger. It is particularly important tominimize the footprint of the housing assembly if the same is to beconveniently gripped or carried. Prior art rule blade assemblies used aconstruction in which the spring width is significantly less than theblade width. When spring power had to be increased in prior artassemblies, spring length and/or particularly spring thickness wereincreased which tended to make the footprints of prior art housingassemblies relatively large and cumbersome, particularly if blade lengthwas long.

Prior art housing assembly construction also typically used fourfasteners located generally in four corners of the housing assembly tosecure the housing assembly together. These fasteners were usually fouraxially extending bolts (where “axial” refers to the direction of theaxis of rotation of the reel defined by the spindle). These fourfasteners were typically disposed outside of the periphery of the reel.This positioning of the fasteners tends to increase the footprint of thehousing assembly. Furthermore, the need for four corners in the housingassembly required that the housing assembly footprint be somewhat squareand this square shape is relatively difficult to grasp was one hand.

There is a need for a spring-powered retractable rule assembly having ahousing assembly footprint size that is as small as possible for a givenblade length and having a footprint with a minimum number of corners andperipherally disposed fasteners to make the housing assembly as easy tohold in a single hand as possible.

BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention is to fulfill the need expressedabove. In accordance with the principles of the present invention, thisobjective is achieved by providing a retractable rule assemblycomprising a housing assembly and a reel rotatably mounted in thehousing assembly. An elongated blade formed of a ribbon of metal havingone end connected to the reel is constructed and arranged with respectto the housing assembly to extend from a position tangential to the reeloutwardly through a spaced opening in the housing assembly. A coilspring formed of a ribbon of metal is a constructed and arranged betweenthe housing assembly and the reel to rotate the reel in the housingassembly in a direction to wind up the elongated blade when extendingoutwardly of the housing assembly opening in a normal concavo-convexcross-sectional configuration onto the reel in an abutting volute coilformation in a flattened cross-sectional configuration. A blade holdingassembly is provided which is manually actuated to hold the blade in anyposition of extension outwardly of the housing assembly opening and torelease the blade from any position in which it is held. The metalribbon of the spring has a width that is 95 percent to 120 percent ofthe width of the metal ribbon of the blade. More preferably, the metalribbon of the spring is 100 percent to 110 percent of the width of themetal ribbon of the blade.

In the more specific aspects of the present invention, it is a furtherobject to provide a retractable rule assembly having a reduced size aspreviously described with the following additional features:

1. The blade has a blade width, thickness and height of concavo-convexcurvature sufficient to enable the blade to stand out arcuately a lengthmeasured along the blade of approximately 11 feet with a horizontallinear length of standout thereof greater than 97% of the arcuate lengthof standout.

2. A retractable rule assembly wherein the elongated blade has a widthin the flattened configuration thereof having a dimension within therange of 1.10″-1.5″, a height in the concavo-convex configurationthereof having a dimension within the range of 0.25″-0.40″ and athickness in either configuration thereof having a dimension within therange of 0.0045″ to 0.0063″.

3. A retractable rule assembly wherein the concavo-convexcross-sectional configuration of the blade includes an arcuate centralsection having a predetermined radius of curvature and integral arcuateend sections each having the same radius of curvature, the radius ofcurvature of the central section being a dimension within the range of0.35″ to 0.60″ and the radius of curvature of each end section being adimension within the range of 1.0″ to 5.0″.

4. A retractable rule assembly wherein a relatively short free endportion of the blade has a clear film of plastic material adhered to aconcave side thereof.

5. A retractable rule assembly wherein the blade has an end hook memberon the free end thereof, the end hook member being formed of sheet metalof a predetermined thickness to include a concavo-convex mountingportion having a U-shaped hook portion bent at a generally right anglefrom an end thereof, the end hook member being mounted on the free endof the blade with the mounting portion thereof secured in limitedsliding engagement with a concave side of the free end of the blade sothat the rule can be measured externally from an exterior surface of theU-shaped hook portion or internally from an interior surface of theU-shaped hook portion, the U-shaped hook portion including a bightsection extending transversely from a convex side of the free end of theblade and spaced leg sections extending beyond transversely spacedcorners of the free end of the blade.

6. A retractable rule assembly wherein the housing assembly includes apair of cooperating housing members, each including an end wall having aperipheral wall extending from a periphery thereof and terminating in afree edge, the housing members being fixed together with their freeedges interengaged by a plurality of bolts extending through one of thehousing members and threadedly engaged in the other at spaced positionsadjacent the peripheral walls thereof and by a fixed reel spindle havinga non-circular interengaging recess-projection connection at each endthereof with the central interior of the adjacent end wall, each end ofthe spindle being interiorly threaded to threadedly receive a bolttherein extending through a central hole in the adjacent end wall andthe recess-projection connection between the central hole and threadedinterior.

7. A retractable rule assembly wherein the housing assembly includes afitment defining a part of the housing assembly opening adjacent aconvex side of the blade, the fitment having a plurality of tangentiallyextending transversely spaced elongated ridges defining surfaces forengaging the convex side of the blade extending tangentially from thereel to said housing assembly opening.

8. The housing assembly includes a bottom wall having an exteriorportion at an end position adjacent the housing assembly opening whichprojects below the exterior surface portion extending therefrom towardan opposite end to provide a finger grip enhancing configuration.

9. The housing opening has a height dimension which exceeds the heightdimension of the blade an amount that is at least approximately equal tothe amount the hook portion extends below the bottom end surface of thehousing assembly at the housing opening.

These and other objectives, features, and advantages of the presentinvention will become apparent from the following detailed description,the accompanying drawings, and the appended claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective few of a tape rule assembly constructedaccording to the principles of the present invention;

FIG. 2 shows a front of elevational view of the tape rule assembly;

FIG. 3 shows a side of elevational view of the tape rule assembly;

FIG. 4 shows a cross-sectional view of the tape rule assembly takenthrough the line 4—4 in FIG. 2 showing a blade thereof in a fullyretracted configuration;

FIG. 5 is a view similar to FIG. 4 except showing the blade in a fullyextended configuration;

FIG. 6 is a cross-sectional view taken through the line 6—6 in FIG. 3;

FIG. 7 is a transverse cross-sectional view taken through a portion ofthe extended blade;

FIG. 8 is a transverse cross-sectional view taken through a portion ofthe blade when the blade is in a flattened configuration;

FIG. 9 is a table showing a comparison of the construction and standoutcharacteristics of a plurality of exemplary prior art tape ruleassemblies with an embodiment of the tape rule assembly constructedaccording to the principles of the present invention;

FIG. 10 is a schematic representation of an extended tape bladeextending from a housing assembly to illustrate the linear length-out,arcuate length-out of the blade and the rotational angle of the housingassembly; and

FIG. 11 is a cross-sectional view of a fragment of the tape ruleassembly taken through the line 11—11 of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-3 show an exterior view of a retractable rule assembly that isgenerally designated 10 and is constructed according to the principlesof the present invention. The rule assembly 10 includes a housingassembly 12 and a reel 14 that is rotatably mounted inside the housingassembly 12 (best seen in the cross-sectional views of FIGS. 4-6). Thereel 14 is mounted in the housing assembly 12 by a reel spindle 15 thatis secured within the housing assembly 12 (FIGS. 4-6). An elongated taperule blade 16 is mounted on the reel 14.

The blade 16 is formed of a ribbon of metal, the preferred metal beingsteel, and the top concave surface of the blade is printed withmeasuring lines and digits (not shown) for measuring lengths anddistances. One longitudinal end 18 of the blade 16 is connected to thereel 14 and a second longitudinal free end 20 of the blade 16 extendsgenerally outwardly of the reel 14. The blade 16 is constructed andarranged with respect to the housing assembly 12 to extend generallyfrom a position tangential of the reel 14 outwardly through a spacedopening 22 provided in the housing assembly 12 (as shown, for example,in FIG. 4).

Preferably the reel 14 is made of a molded plastic and is provided withslots or openings 24, 26 in a central cylindrical wall portion 28thereof. The one end 18 of the blade terminates in a hook-like structure30 that hookingly engages an edge of the wall portion 28 of the reel 14at opening 24 to connect the end 18 of the blade 16 to the reel 14(FIGS. 4, 5).

A coil spring 32 has a construction and arrangement between the housingassembly 12 and the reel 14 to rotate the reel 14 with respect to thehousing assembly 12 in a direction to wind the elongated blade 16 aboutthe reel when the blade 16 is extending outwardly of the housingassembly opening 22. The coil spring 32 is generally enclosed within thecentral wall portion 28 of the reel 14 (FIGS. 4-6). One longitudinal end35 of the coil spring 32 hookingly engages an edge of the wall portion28 of the reel 14 that defines the opening 26; a second longitudinal end37 of the blade 16 hookingly engages the spindle 15. The spindle 15 isrigidly mounted to the housing assembly 12 in a manner considered indetail below. Preferably the spring 32 is a thin, flat ribbon of metal,the preferred metal being steel.

The blade 16 is generally movable between a fully retracted positionoutwardly of the housing assembly 12 to a fully extended position. Thefully retracted position of the blade 16 is shown in FIG. 4 and thefully extended position of the blade is shown (in fragmentary view) inFIG. 5. It can be appreciated from a comparison of FIG. 4 and FIG. 5that as the blade is unwound from the reel 14, the coil spring 32 iswound around the rigidly fixed spindle 15. This winding of the springaround the spindle stores energy in the spring to provide spring poweredrewinding of the blade 16 around the reel 14 when the extended blade isreleased.

The blade 16 is constructed of a ribbon of sheet metal that is shapedduring the manufacturing to have a normal or memory configuration thathas a generally arcuate or concavo-convex transverse cross-section. Whena portion of the blade 16 is wound about the reel 14, the wound portionhas a flat transverse cross-section (FIGS. 6 and 8) and the wound layersof the coiled blade provide the wound blade with an abutting volute coilconfiguration. A representative transverse cross-section of the extendedblade 16 showing its concavo-convex configuration is illustrated in FIG.7. It can therefore be understood from a comparison of FIGS. 4-5 (andfrom a comparison of FIGS. 7-8) that when the blade 16 is wound aroundthe reel 14, it has the flat cross-section of FIG. 8 and when the blade16 is withdrawn from the housing assembly 12 to measure an object, itreturns to the concavo-convex cross-section shown in FIG. 7. Thus, thecoil spring 32 is constructed and arranged between the housing assembly12 and the reel 14 to rotate the reel 14 about the spindle with respectto the housing assembly 12 in a direction to wind up the elongated blade16 when extending outwardly of the housing assembly opening 22 in anormal concavo-convex cross-sectional configuration onto the reel 14 inan abutting volute coil formation in a flattened cross-sectionalconfiguration. The concavo-convex cross-section provides the extendedblade with rigidity and maintains the blade essentially straight in thelongitudinal direction.

The concavo-convex cross-section of the blade generally provides theunsupported blade 16 with blade standout. As described in greater detailbelow, the blade 16 has a blade width, thickness and height ofconcavo-convex curvature sufficient to enable the blade 16 to standoutarcuately a length measured along the blade of at least 10.5 feet with ahorizontal linear length of standout thereof that is greater than 97percent of the arcuate length of standout. As also described in greaterdetail below, the concavo-convex transverse cross-section of the blade16 is provided with a geometry that also improves blade standout.

Generally, one skilled in the art will understand that the length ofblade standout depends on many factors, including (but not limited to)blade width (i.e. the transverse width of the blade measured when theblade is in its flattened condition shown, for example, in FIG. 8 anddesignated F); the height of the blade 16 in the concavo-convexconfiguration (designated H in FIG. 7); blade thickness (designated T inFIG. 7); and the geometry of the blade transverse cross-section when thesame is in its normal concavo-convex than configuration. Preferably, theblade 12 has a width in the flattened condition thereof having adimension within the broad range of from approximately 1.10 inches toapproximately 1.5 inches; a height H in the concavo-convex configurationthereof having a dimension within the broad range of approximately 0.25inch to approximately 0.40 inch; and a thickness in either configurationthereof having a dimension within the broad range of approximately0.0045 inch to approximately 0.0063 inch. More preferably, the blade 12has a width in the flattened condition thereof having a dimension withinthe narrower range of from approximately 1.25 inches to approximately1.39 inches; a height H in the concavo-convex configuration thereofhaving a dimension within the narrower range of approximately 0.30 inchto approximately 0.35 inch; and a thickness in either configurationthereof having a dimension within the narrower range of approximately0.005 inch to approximately 0.0056 inch. Most preferably the blade 16width is approximately 1.25 inch, the blade height H is approximately0.32 inch and the blade thickness T is approximately 0.0051 inch. Ablade constructed according to these principles has a blade standout ofup to approximately 13 feet. More specifically, a blade constructionhaving dimensions within the broadest ranges identified immediatelyabove for the width F, height H and thickness T can have a bladestandout in the preferred broad range of at least 10.5 feet toapproximately 13 feet; a blade construction having dimensions within themore preferred narrower ranges identified immediately above for thewidth F, height H and thickness T can have a blade standout in the rangeof at least 10.5 feet to approximately 12.5 feet; and a bladeconstruction having the most preferred dimensions identified immediatelyabove for the width F, height H and thickness T has a blade standout ofapproximately 11 feet.

The concavo-convex cross-section of the blade 16 has a unique geometry(shown in FIG. 7) that increases in the standout ability. Theconcavo-convex cross-sectional configuration of the blade 16 includes anarcuate central section 36 and integral arcuate end sections 38. Eacharcuate end section 38 has the same radius of curvature (indicated forone of the two end sections 38 in FIG. 7 by the line designated R1). Thecentral section 36 has a radius of curvature designated R2 (FIG. 7). Theradii of curvature R1 for the two end sections 38 are greater than theradius of curvature R2 of the central section 36. The central sectionhaving a radius R2 extends through an angular extent designated X inFIG. 7. Preferably angle X is approximately 84 degrees.

Preferably the arcuate central section 36 has a radius of curvature R2that is a dimension within the broad range of approximately 0.30″ toapproximately 0.60″; and the radius of curvature R1 of each end section38 is a dimension within the broad range of approximately 1.0″ toapproximately 5.0″. More preferably the arcuate central section 36 has aradius of curvature R2 that is a dimension within the narrower range ofapproximately 0.40″ to approximately 0.50″ and the radius of curvatureR1 of each end section 38 is a dimension within the narrower range ofapproximately 2.0″ to approximately 4.0″. Most preferably, the arcuatecentral section 36 has a radius of curvature R2 of approximately 0.46″and the radius of curvature of each end section R1 is approximately3.0″.

The transverse cross-sections of prior art tape blades are eitherconstant curves (i.e., constant radius of curvature) or are constantcurves in the center of the blade with straight (i.e. flat) sections ateach transverse end of the cross-section when the blade is extended.Blades constructed to have either of these basic cross-sections are lessstable during blade standout and show a greater tendency to buckle thanblades having cross-sections constructed according to the presentinvention.

FIG. 9 shows a comparison of the construction and standout capabilitiesof three prior art rule assemblies (shown in the first six rows of thetable and indicated with a bracket) with a preferred embodiment of therule assembly 10 constructed according to the principal of the presentinvention (shown in the last five rows of the table). As the firstcolumn of FIG. 9 indicates, typical prior art rule blades did not exceedone inch in width (measured in the flattened, coiled configuration ofthe blade). The second column indicates that prior art blade thicknessfor a one inch blade ranged from 0.0045 inch to 0.0056 inch and producedblade having a standout length of from approximately 7 feet toapproximately 9 feet as indicated in FIG. 9, the third column.

The embodiment of the rule assembly constructed according to theprinciples of the present invention shown in FIG. 9 has a blade width of1.250 inches (in the flat configuration) and a blade thickness of 0.0051inch. Preferably, the blade described in FIG. 9 has a concavo-convexcross-section in the extended configuration as described above and asshown in FIG. 8.

The last five columns in FIG. 9 compare the standout characteristics ofthe three prior art tape assemblies with the tape assembly 10constructed according to the principles of the invention. The standoutcharacteristics of the blade of a given tape assembly are bestunderstood by comparing the arcuate (i.e., actual) length-out measuredalong the surface of the blade with the linear length-out of the blade.These two characteristics are often expressed as a percentage of linearlength-out to arcuate length-out. FIG. 10 shows a schematic diagram thatillustrates what is meant by arcuate length-out and linear length-out.

Arcuate length-out is represented by arcuate line C in FIG. 10 and is ameasure of the total length of the extended portion of the blade. Linearlength-out is designated B in FIG. 10 and is a measure of the linearlength of the projection of the extended blade on an imaginaryhorizontal surface below the tape assembly 10. Line A designates theheight the housing assembly 10 is required to be above the horizontalsurface when the housing assembly 12 is angularly oriented with respectto the surface at an angle D to position the arcuately extending bladeso that the free end thereof just touches the surface. Thus, angle Dgenerally represents the degree of tape rule housing assembly rotation(with respect to the horizontally extending surface) required to achievemaximum standout for a given length of extended tape.

The comparison of the prior art and the present invention given in FIG.9 indicates that the maximum prior art arcuate length-out that could beachieved with a one inch wide blade was approximately nine feet. Becauseof the relatively shallow (relative to the present invention)cross-sectional blade height H of approximately 0.21 inch (not shown inFIG. 9) typically used in prior art one inch blades and because of therelatively high thickness of the metal of the prior art blades (whichthickness is required for the arcuate length-out to be achieved),however, the linear length-out B was approximately 93 inches. Thisresults in a percent of linear to arcuate length-out of approximately 86percent. It can be appreciated that the third embodiment of the priorart shown in the fourth through the sixth rows of FIG. 9 showsrelatively little bending for seven feet of standout (96% linear toarcuate length-out), but that this embodiment bends a very large degreewhen two additional feet of the blade are extended. This high degree ofarcuate bending of the 1 inch blade at standout lengths approaching 9feet makes the task of measuring a large distance difficult for a singleperson using the prior art tape rule assembly. As indicated in FIG. 9,the present invention provides a rule assembly that can achieves sevenfeet to approximately 11 feet of arcuate length-out while maintainingthe percent of linear to arcuate length-out in the approximate range of99 percent to 98 percent. This greatly facilitates the task of measuringa length for the tape assembly user. Greater degrees of standout with acomparable percentage of linear to arcuate length-out can be achieved bymaking the blade wider. It is, for example, within the scope of thepresent invention to provide a blade width of 1.5 inches or greater.

It can be understood by one skilled in the art that the 1.25 inch bladewidth of a preferred embodiment of the assembly 10 allows the bladeheight H to be increased without increasing the overall blade curvatureto a degree that would make reading the gradations and lettering printedon the concave surface of the blade 16 difficult. This constructionresults in a blade with relatively high height H that is also easy toread. (In contrast, one inch blades having a curve height of theextended blade of over 0.21 become very difficult to read and are thusnot commercially practical.) Increasing the blade width of the blade ofthe present invention also allows the printing on the blade to be madelarger, thus making measurements easier by making the blade easier toread. When the preferred 1.25 inch blade (flat width F) is in itsconcavo-convex cross-sectional configuration (FIG. 7), the height Hthereof, as mentioned above, is approximately 0.32 inch and the curvedor arcuate width W is approximately 1.018 inches. This relatively widewidth W of the extended blade also facilitates reading a measurementfrom the blade 16.

The blade of the rule assembly 10 is thus able to achieve theapproximately 11 feet of standout while improving the percent of linearto arcuate length-out relative to the prior art. This length of standoutis achieved while the bottom surface of the housing is angledapproximately 45 degrees with respect to the horizontal surface S (asindicated in the right most column of FIG. 9) which is comparable to thethree prior art rule assembly embodiments shown in FIG. 9.

One skilled in the art will appreciate that when the rule assembly 10 isprovided with a 33 foot long blade, a coil spring 32 must be provided toaccommodate outward movement of the blade 16 to its fully extendedposition. It can be appreciated that it is desirable to construct a ruleassembly 10 so that the housing assembly 12 is small enough and compactenough to fit easily in one hand of a user. Because the rule assembly 10has a wide blade, the width of the housing assembly 12 is comparablywide. It is desirable to construct a retractable rule assembly 10 sothat the height and length of the housing assembly 12 (also called the“footprint” of the housing assembly 12) are as small as possible.Because both the spring 32 and the blade 16 can be quite long in someembodiments of the invention (up to approximately 33 feet of bladelength, for example), the spring 32 must be carefully constructed sothat it provides sufficient spring forced to retract the fully extendedblade and yet fits within a housing assembly 12 having a footprint thatis dimensioned to easily fit in a user's hand.

The coil spring is constructed of a coiled ribbon of metal (typicallysteel). The spring force provided by the spring is approximatelydirectly proportional to the spring width and the spring thickness. Athick spring undesirably increases the height and length of the housingassembly 12, however. It has been found that the most desirableconstruction of a rule assembly constructed according to the principlesof the present invention has a coil spring that is relatively thin andrelatively wide compared to prior art springs. Preferably the spring 32of the rule assembly 10 has a width that is approximately 95 percent toapproximately 120 percent of the width of the blade (for a given bladewidth in the broad range set forth above for the flattened blade). Morepreferably, the spring has a width that is approximately 100 percent toapproximately 110 percent of the width of the metal ribbon of the blade,and is most preferably 100% of (i.e., equal to) the blade width (asshown in FIG. 9). Because the spring width is relatively great, thespring can be made the same thickness as or thinner than the blade 16.The reduction in the spring thickness relative to blade thickness (ascompared to the prior art), allows the housing assembly 12 to beconstructed so that it has a minimal footprint to provide a housingassembly 12 that can be easily gripped in one hand.

Typical springs used with prior art one-inch blades have a width that isless than the width of the blade, usually in the range of 0.8 to 0.89inch. FIG. 9 shows a typical value of 0.875-inch for the spring widthfor all three embodiments of the one-inch blades described in thefigure. Prior art spring thickness ranges from about 0.0051 to about0.0060 inch. Generally, prior art spring thickness is approximately0.0003-0.0006 greater than the blade thickness. Thus, prior artconstruction uses springs that are thicker and significantly narrowerthan the blade. It can be appreciated that although it is possible touse this prior art construction and the present invention, it isundesirable because the relatively thick spring of the prior art wouldresult in a housing assembly footprint that too large to fit comfortablywithin the average user's hand. Thus there is a need for a new springconstruction that can be used with the blade 16 that will allow thefootprint of the housing assembly to be made small to be comfortablygrippable using one hand.

It can thus the understood that the relatively wide spring allows thethickness of the spring to remain relatively small and this allows thefootprint of the housing assembly to be small enough to be easilygripped in a single hand of the most users. More specifically,preferably, when the spring width is approximately equal to the bladewidth, the spring 32 of the present invention is 0 percent to 10 percentthinner than the blade 16. As another example, if the spring 32 is madeone hundred twenty percent the width of the blade 16, the spring 32 ispreferably 0 percent to 25 percent of thinner than the blade. In termsof actual measurement, this means that typically the spring thickness isup to 0.0005 inch thinner than the thickness of the blade. Furthermore,because the spring of the present invention is made wide relative to thewidth of the blade, the overall length of the spring can be made shorterrelative to the length of prior art springs for comparable measuringblade 16 lengths. For example, a typical one inch wide, 25 foot longprior art blade has a spring that is approximately 240 inches in length;the length of a wide spring 32 constructed according to the principlesof the present invention for the rule assembly 10 having a 25 foot bladeis approximately 230 inches.

By increasing the spring width of the spring 16, the thickness of thespring can be decreased and the length decreased while still providingsufficient spring force to retract the blade without increasing thefootprint of the housing assembly to an undesirable degree. Examples ofspecific housing assembly 12 heights for particular blade lengths willbe considered below after other structural details of the constructionof the rule assembly 10 are considered.

The housing assembly 12 is further constructed to easily and comfortablyfit in a hand of the user because it optimizes the use of space withinthe housing assembly 12 to house the blade 16, coil spring and othercooperating components. The details of the internal structure of thehousing assembly 12 and the blade 16 mounted therein are shown in FIGS.4-6 and 11. Preferably the housing assembly 12 and the reel 14 areconstructed of a molded plastic. As best appreciated from FIG. 6, thehousing assembly 12 includes a pair of cooperating molded plastichousing members 40, 42. Each housing member 40, 42 includes an end wall44, 46, respectively, having a peripheral wall 48, 50, respectively,extending from a periphery thereof and terminating in a free edge 52,54, respectively. The pair of cooperating housing members 40, 42 aremovable toward one another in an axial direction into cooperatingrelation to define the housing assembly (where “axial direction” refersto the direction of the axis of rotation of the reel defined by thespindle).

When the housing members 40, 42 are fixed together in the assembled ruleassembly 10, the free edges 52, 54 are interengaged as shown in FIG. 6.A plurality of axially extending bolts 58 extend through one of thehousing members 42 and threadedly engage the other housing member 40(FIG. 11) at spaced positions adjacent the peripheral walls 48, 50. Thehousing members 40, 42 are also fixed together by the threadedengagement of bolts 68 with the fixed reel spindle 15. The axiallyextending spindle 15 is fix at a central portion of the housing assembly12. Specifically, the fixed spindle 15 has a noncircular interengagingrecess-projection connection (shown in FIG. 6 and described below) ateach end thereof generally with a central interior region 62, 64,respectively, of the end walls 44, 46 of the housing assembly 12. Eachend of the fixed spindle 15 is interiorly threaded to threadedly receivethe bolts 68 therein. The bolts 68 extend through central holes 70, 72formed in the respective adjacent end walls 44, 46 of the housingassembly and threadedly engage internal threading 73 in each end of thespindle 15. Each bolt 68 extends through a recess-projection connection,generally designated 75, when each bolt 68 is disposed in a respectivecentral hole 70, 72 and threaded interior 73. A metal clip 77 is securedto one side of the housing assembly by one of the bolts 68.

Preferably the fixed spindle 15 is constructed of a molded plastic ornylon. The construction of the recess-projection connections 75 betweenthe ends of the spindle 15 and the walls 44, 46 is shown incross-section in FIG. 6. Each recess-projection connection 75 isidentical. Specifically, projections 74 having exterior noncircularcross-sections are integrally formed on the walls 44, 46 and arereceived within recesses 76 having complementary non-circular interiorcross-sections formed on each end of the spindle 15. The noncircularinterior and exterior cross-sections cooperate to prevent rotation ofthe spindle 15 with respect to the housing assembly 12 when the ends ofthe spindle 15 are mounted on the projections 74 in the assembled ruleassembly 10. Each end of the spindle 15 extends through a hole 79 ofcircular cross-section formed in opposite sides of the reel 14. Theportions of the spindle 15 that extend through the holes 79 in the reel14 have circular exterior cross sections. A flange 81 on the spindle 15engages an annular groove 83 in the reel 14 surrounding the hole 79 toguide the rotation of the reel on the spindle. Thus, the reel 14 isrotatably mounted on the spindle 15 for bi-directional rotationalmovement of the reel with respect to the housing assembly 12. As canbest be appreciated from FIGS. 4 and 6, the spindle 15 is internallyslotted to receive the one longitudinal end 37 of the spring 32 tothereby secure the one end 37 of the spring to the spindle.

The molded plastic reel 14 includes two reel members 78, 80 (FIG. 6).Reel member 78 includes the integral cylindrical wall portion 28 aboutwhich the blade 12 is wound. Reel member 80 is essentially disk shaped.Each reel member 78, 80 includes an outwardly extending cylindrical wallportion 88, 90, respectively, formed around the hole 79. An annular edgeportion 84 on the wall portion 82 is received within an annular groove86 formed within reel member 80 to help hold the reel 14 together. Theabutting engagement of the wall portions 88, 90 on the reel with the endwalls 44, 46 of the housing assembly 12 maintain the edge portion 84within the groove 86 in the assembled rule assembly.

The housing members 40, 42 include portions along the abutting freeedges thereof 52, 54, respectively, of tongue and groove construction(FIG. 6) to help secure the molded housing members 40, 42 of theassembled rule assembly 10 together. Specifically, at a top portion ofthe housing assembly 12, a wall portion 92 formed on edge 54 is receivedwithin a groove 94 formed along a portion of the edge 52; and anintegral wall portion 93 formed on edge 52 is disposed in underlying,abutting relation to wall portion 50 of the housing member 44. At abottom portion of the housing assembly 12, a wall portion 95 formedalong a length of edge 54 is received within a recess 97 formed on aportion of the wall portion 48 of housing member 40.

When viewed from the side elevational view, the housing assembly 12includes only two corner portions (see FIG. 4, for example), generallydesignated 96, 98. One corner 96 is adjacent the housing assemblyopening 22 and the other corner portion 98 is at an opposite bottom endof the housing assembly 12. The two bolts 58 are positioned in the onlytwo corner portions 96, 98, respectively, of the housing assembly 12.Thus, it can be appreciated that the housing assembly 12 is securedtogether using threaded fasteners in only three locations (from thepoint of view of one looking at the side elevational view of, forexample, FIG. 4): at the opposite corners 96, 98 (bolts 58) at thebottom portion of the housing assembly 12 and in the center of thehousing assembly 12 (bolts 68). This use of the bolts 68 on oppositeends of the reel spindle 15 allows the housing assembly 12 to be securedtogether without using any bolts in a peripheral top portion or portionsof the housing assembly 12.

This arrangement of the bolts helps reduce the size of the footprint ofthe housing assembly 12 to allow the housing assembly 12 for a 33-footlong blade constructed according to the principles of the invention tohave up to 13 feet of blade standout, for example, to easily fit in ahand of a user. Specifically, it is within the scope of the invention toprovide tape assemblies constructed according to the principles taughtherein wherein the height (and length) of the housing assembly does notsubstantially exceed 3.65 inches for a blade length that is at mostapproximately 33 feet; wherein the height (and length) of the housingassembly does not substantially exceed 3.45 inches for a blade lengththat is at most approximately 30 feet; and wherein the height (andlength) of the housing assembly does not substantially exceed 3.25inches for a blade length that is at most approximately 8 meters.

As best appreciated from FIGS. 3-4, because the housing assembly doesnot require bolts in the upper periphery of the housing assembly 12, thetop portion 108 of the housing assembly 12 can be made to have arelatively arcuate profile (FIG. 2, for example) that generally conformsto the profile of the reel, thus minimizing the footprint of the housingassembly 12, eliminating corners in the upper portion of the housingassembly and providing a comfortable curved top surface to receive thepalm of a user's hand. This arc-shaped upper surface of the housingassembly 12 also increases impact resistance of the housing assembly 12in case the assembly 10 is dropped.

A peripheral portion of housing assembly 12 is provided with arubber-like coating 110 around the gripped portion of the housingassembly 12 to provide increased frictional engagement between thehousing assembly and a user's hand and to provide a relatively softcomfortable surface for the user's hand. The housing assembly 12includes a bottom wall 109 (FIGS. 4-5) having an exterior portion 107 atan end position adjacent the housing assembly opening 22 which projectsbelow an exterior surface portion 108 extending therefrom toward anopposite end 113 of the bottom wall 109 to provide a finger gripenhancing configuration, generally designated 119 for a gripping hand ofthe user. More specifically, the bottom wall 109 (FIGS. 3-4) has aforward end portion 107 adjacent the housing assembly opening 22 and arearward end portion 113 at the opposite end of the bottom wall 109; theportion 108 of the wall 109 therebetween is generally recessed toprovide the finger grip enhancing configuration 119 for the grippinghand of the user. This recessed area or gripping area 119 on the bottomof the housing assembly 12 is preferably completely covered with theovermolded rubber or rubber-like polymeric material. It can thus beappreciated that the housing assembly 12 is constructed to be easilyheld in one hand of a user such that the user's fingers engage thefinger grip enhancing portion 119 and the user's palm and thumb aregenerally in overlying relation with a top portion of the housingassembly.

The housing assembly includes a fitment 118 (FIG. 11) which forms a partof the housing assembly opening 22 adjacent a convex side of the blade16. The fitment 118 is an essentially U-shaped structure having atransversely extending cross member 115 and two upstanding arms 117extending upwardly from opposite sides of the cross member 115. Thecross member 115 defines the lower edge of the housing opening; a bottomsurface 170 of the cross member 115 is flush with the adjacent surfaceportion 107 of the bottom wall 109 so that a bottom surface portion 170of the fitment 118 forms part of the bottom surface of the housingassembly 12 adjacent the opening 22. The fitment 118 is preferably anintegral molded plastic structure. The fitment 118 is held withinappropriately sized opposing recesses 121, 123 (FIG. 11) formed in therespective housing members 40, 42 and which recesses are disposed onopposite sides of the opening 22 when the housing members 40, 42 aresecured together. The cross member 115 of the fitment 118 has aplurality of tangentially extending, transversely spaced elongatedridges 120 which define surfaces 125 along the bottom of the opening 22for engaging and supporting the convex side of the blade 16 extendingtangentially from the reel 14 of the housing assembly opening 22. Thus,the ridges 120 slidably engage the convex side of the blade 16 andprovide a low friction engagement between the housing assembly 12 andblade 16.

A holding assembly, generally designated to 124, is constructed andarranged to be manually actuated to hold the blade 16 in any position ofextension outwardly of the housing assembly opening 22 and to releasethe blade 16 from any position in which it is held. The structure andoperation of the holding assembly 124 is best appreciated from acomparison of FIGS. 4-5. The holding assembly 124 includes a holdingmember 126 mounted on the housing assembly 12 for movement in oppositedirections between a normally inoperative position (FIG. 4) and aholding position (FIG. 5). It can be appreciated that the blade holdingmember 126 is an arcuate member that is movable along an arcuate pathbetween the two positions as aforesaid. The holding member 126 has aninterior free end portion 128 that is movable into wedging engagementwith the tangentially extending portion of the blade 16 to engage andhold the blade against an interior holding structure 130 (FIG. 5) on thehousing assembly 12 when the holding member 126 is in its holdingposition. The free end portion 128 includes a central recess 129 (FIG.2, for example) that is described in detail below. The holding member126 has an exterior thumb engaging portion 132 configured to be moveddigitally to selectively move the holding member 126 from its normallyinoperative position and its holding position. The exterior thumbengaging portion 132 is best seen in FIGS. 1-2.

Preferably the holding member 126 is an integral structure made of anappropriate durable flexible plastic. The thumb engaging portion 132 isconnected by an integral outwardly extending neck portion 134 to anelongated arcuate flexible body portion 133 that terminates in theinterior free end 128. The outwardly extending portion 134 is slidablyheld within and guided by a slot 136 formed within a front part ofhousing assembly 12 by the members 40, 42. The movement of a lowerportion of the holding member 126 is guided by a pair of tabs 131integrally formed on respective housing members 40, 42 (only one tab isshown in the figures). An integral locking structure 138 on the holdingmember 126 engages holding structure 140 (FIG. 5) integrally formed onthe housing assembly 12 to releasably lock the holding member 126 in theholding position in wedging engagement with the blade 16.

More specifically, to lock the blade 16 in a given position ofextension, the user (while holding the blade 16 outwardly of the housingassembly 12 against the spring force of the coil spring 32) slides thethumb engaging portion 132 downwardly with respective to the housingassembly 12 causing the locking structure 138 to slide over a rampedsurface 142 on the holding structure 140 and causing the free end 128 tomove in a locking direction with respect to the blade 16. The flexibleplastic locking structure 138 bends resiliently outwardly slightly as itpasses over the holding structure 140. After the free end 128 contactsthe blade 16, continued movement of the thumb engaging portion 132 inthe locking (downward) direction thereafter wedges the free end 128 ofthe flexible body portion 133 against blade 16 to hold the blade 16 inplace against the spring force of the coil spring 32 and moves thelocking structure 138 into abutting engagement with a locking surface141 on the holding structure 140. The holding member flexes slightly asthe free end 128 is wedged against the blade 16. The abutting engagementbetween the locking structure 138 and the locking surface 141 locks theholding member 126 in its holding position. It can be understood fromFIG. 5 that the blade 16 is held in an extended position (against thespring force of the coil spring 32) between the free end 128 of the bodyportion 133 and the interior holding structure 130 by the downward forceexerted by the wedged body portion 133. The interior holding structure130 (not visible in detail) is a series of longitudinally spaced,transversely extending ribs that are constructed and arranged to supportthe convex side of the blade 16. When viewed from the point of view ofFIG. 5 (i.e., on a transversely directed line of sight), the topsurfaces (not visible in the FIGS.) of the ribs cooperate to provide agenerally downwardly sloped support (in a direction toward the opening22) for the blade 16; and when viewed from the front, (i.e., on alongitudinally directed line of sight) the top surfaces (not visible inthe figures) of each rib of the interior holding structure 130 aretransversely spaced in a concave array to receive and support the convexside of the blade.

To release the blade 16, the user pulls upwardly on the thumb engagingportion 132 which causes the locking structure 138 on the plasticholding member 126 to move resiliently outwardly and past the lockingsurface 141 to release the holding member 126 from engagement with ablade 16. The holding member 126 resiliently returns to its normalarcuate shape. It can be appreciated from FIG. 2 that the recess 129 onthe free end 128 of the holding member 126 defines two transverselyspaced teeth 147 which have spaced arcuate side surfaces 144 sized toconform to the concave surface of the blade 16 to hold the same inlocked position.

It can be understood that the use of the holding member 126 when ameasurement is being taken is optional. When taking a measurement, theuser typically holds the housing assembly 12 in one hand and manuallypulls the blade 16 out of the housing assembly 12 with the other hand.When a sufficient length of blade 16 has been withdrawn from the housingassembly 12, the user can lock the blade 16 with respect to the housingassembly 12 using the holding member 126 to prevent the blade 16 fromretracting back into the housing assembly 12 (under the spring force ofspring 32) when the user releases the blade 16. When the measurement hasbeen taken, the user simply releases the holding member 126 from holdingengagement with the blade 16 by moving the free end 128 thereof out ofwedging engagement with the blade 16 in the manner described above. Ifthe holding member 126 is not used during the taking of a measurement,the user can simply hold the blade 16 with his other hand while themeasurement is being taken or, alternatively, the hook member 34 can beplaced in hooking engagement with the workpiece to hold the blade 16outwardly of the housing assembly 12 in a controlled and steady manneragainst the spring force of spring 32 while the measurement is beingtaken.

When the blade 16 is released after taking the measurement, the spring32 rotates the reel 14 with respect to the housing assembly 12 in ablade-winding direction to wind the blade 16 around the reel 14. Arelatively short free end portion of the blade 16 has a clear film 158of plastic material adhered to the concave side thereof (FIG. 11) toprotect the blade 16 while the same is out of the housing assembly 12and while the blade 16 is being retracted under the spring force of thespring 32 back into the housing assembly 12. Preferably the film is madeof polyurethane and is adhered to the blade by an acrylic adhesive. Itis also contemplated to use Mylar® and Nylon® to construct the film.Preferably the film has a thickness dimension within the range ofapproximately 0.006 inches to approximately 0.014 inches. It is withinthe scope of the invention to apply this film to the blade of any knowntape rule assembly.

Preferably the self adhering film 158 is placed over several leadinginches (preferably within a broad range of approximately 2 inches toapproximately 12 inches) of the free end 20 of the blade 16, includingthe portion of the blade on which the hook member 34 is disposed so thatpreferably the film goes under the hook member 34 all the way to thefree end 20 of the blade 16. More preferably, the film 158 is applied alength from the free end 20 of the blade 16 that is less than 10.5inches; and most preferably, the length of the blade 16 from the freeend thereof that is covered by the film 158 is approximately 6 inches.It is generally desirable to have the film-covered portion end atapproximately the point on the blade 16 where the volutes of the coiledblade are in overlying relation to one another when the blade 16 is inits fully retracted configuration. Typically in a tape rule assembly,the tape blade starts to wrap on itself at approximately 9.5 inches whena typical reel size of approximately 2.9 inches in outer diameter isused in the construction. The film 158 is provided because most failuresin a rule blade 16 occur within the first six inches of the free end ofthe blade 16 from cracks or tearing. The cracks or tearing occur becausewhen the blade is wound back around reel under the spring force of thecoil spring, the free end of the blade tends to “whip” as it enters theopening 22, causing the last several inches of the blade 16 to hitagainst the housing assembly 12. This can cause cracking or breaking ofthe free end of the blade 16 over time. The protective film 158 preventsthese cracks and tears and other damage to the blade 16 associated withblade whipping.

The free end of the blade 16 is frequently handled by the user and thishandling can over time cause the numbering and markings on the concaveside of the blade 16 to wear off or become difficult to read. The film158 prevents this damage because it covers the numbering and markings onthe free end of the blade and thereby protects the same from being wornoff.

The construction of the hook member 34 and the manner in which it isdisposed on the free end 20 of the blade 16 is best seen in FIGS. 1-4,11. Preferably the end hook member 34 is formed of sheet metal ofpredetermined thickness and includes a concavo-convex mounting portion150 (FIG. 11) having a U-shaped hook portion 152 bent at a generallyright angle from an end of the concavo-convex mounting portion 150. Thehook member 34 is mounted on the free end 20 of the blade 16 with themounting portion 150 thereof secured in limited sliding engagement witha concave side of the free end 20 of the blade 16 and in overlyingrelation thereto.

More specifically, the mounting portion 150 is provided with large holes167 (FIG. 4) and a plurality of rivets 169 extend through the holes 167to slidably mount the hook member 34 to the blade 16 for limitedlongitudinal relative movement between the hook member 34 and the blade16 (i.e., the diameter of each hole 167 is greater than the diameter ofthe associated rivet 169 by an amount approximately equal to the desiredamount of hook movement). The limited sliding engagement allows theblade 16 to be measured externally from an external surface 161 of theU-shaped hook portion or internally from an internal surface 163 of theU-shaped hook portion 152. In other words, the sliding movement of thehook member 34 allows an accurate measurement to be taken with eithersurface 161 or 163 in abutting relation with the workpiece; the holdingmember 34 slides longitudinally with respect to the blade 16 a distanceapproximately equal to the thickness of the hook portion 152 (where thethickness is measured from surface 161 to surface 163) so that ameasurement taken with either surface 161 or 163 in abutting engagementwith the workpiece will yield an accurate measurement.

The U-shaped hook portion 152 includes a bight section 160 extendingtransversely downwardly from a convex side of the free end of the blade16 and spaced leg sections 162 extending beyond transversely spacedcorners 171 of the free end of the blade. The bight section 160 of thehook portion 152 of the hook member 34 provides an under-catch structurethat can hookingly engage a workpiece to facilitate extension of theblade 16 and to temporarily secure the blade to the workpiece while ameasurement is being taken. As can be appreciated from FIG. 11, the legsections 162 extend beyond the longitudinally extending edges of theblade 16 to provide a side catch surface on each side of the blade that16 can be used to hook the blade to an object or workpiece. The sidecatch structure provided by the legs 162 can function to secure the freeend of the blade 16 during a measurement. The side catch structureprovided by the leg sections 162 also allow the blade 16 to be easilyand steadily held in a tilted position relative to a surface of theworkpiece, thereby allowing a longitudinally extending edge of the blade16 to be held against the workpiece. More specifically, when the convexside of the blade 16 is against the workpiece, the longitudinal edgesare normally spaced from the surface because of the concavo-convexcross-section of the blade 16. The legs 162 of the hook member 34provide a side catch that can be hooked over an edge of the workpiece toallow the user to hold steadily a longitudinal edge of the blade veryclose to or directly against the workpiece when the convex side of theblade 16 is against the workpiece, which facilitates reading ameasurement. This is helpful in taking measurements because the curveheight H of the cross section is preferably approximately 0.32 of aninch so that the curve height of the blade is relatively high.

The upper portions of the leg sections 162 extend generally upwardly andoutwardly above the concave side of the blade 16 (FIG. 11) to providestructure above the concave surface of the blade 16 to hookingly engagethe workpiece to facilitate extension of the blade 16 and to hold thefree end of the blade 16 while a measurement is being read. For example,the blade 16 can be placed against a workpiece such that the concaveside of the blade 16 is facing the workpiece and such that the oppositelongitudinal edges of the blade 16 abut a surface on the workpiece at apoint where they measurement is to be read. When the blade 16 is in thisposition, the upwardly extending portions of the legs 162 on the hookmember 34 can be used to hold the free end 20 of the blade 16 againstthe workpiece.

It can also be appreciated from FIGS. 1-2 that the hook-shaped portion152 of the hook member 34 provides an aesthetically pleasing “face”appearance on the front of the rule assembly 10 when the blade 16 is inthe fully retracted position. Transversely spaced corners 171 on thefree end 20 of the blade 16 are mitered (FIG. 4) inwardly from oppositelongitudinal edges of the blade 16; the leg sections 162 of the hookmember 34 extend beyond the mitered corners 171 on the opposite edges ofthe end 20 of the blade 16. The mitered corners 171 prevent the userfrom being scratched or cut by the corners on the end of blade 16.Preferably each corner 171 is mitered inwardly from the respectiveopposite longitudinal edge starting at a distance of approximately{fraction (3/32)} of an inch from the free end of the blade 16.

Preferably, the housing opening 22 has a height dimension that exceedsthe height dimension of the hook member mounting portion 150 and itsconnection with the free end of the blade 16 by an amount which is atleast approximately equal to the amount the hook portion 152 of the hookmember 34 extends below a bottom end surface 170 of the housing assembly12 at the housing opening 22 when the hook member 34 is at the housingopening 22 (FIG. 11). This height of the opening 22 is provided toprevent possible damage to the hook member 34 when the blade 16 is fullyretracted and the hook member 34 is impacted (by dropping or the like)in a direction that tends to move the hook member 34 upwardly withrespect to the opening 22.

The details of the construction of the housing opening 22 can beappreciated from FIGS. 4 and 11. It can be appreciated that the axiallyextending fastener 58 in the corner 96 must be spaced upwardly in thehousing assembly 12 a sufficient distance to allow the opening 22 tohave sufficient height to protect the hook member during impact. Thelocation of this fastener 58 in the corner 96 is restricted by thedimensions of the corner 96. Specifically, the arcuate path followed bythe arcuate holding member 126 between its inoperative position and itsblade holding position defines the interior extent of the bottom corner96 of the housing assembly and a lower front wall portion 200 at thefront of the housing assembly 12 generally defines the forward extent ofthe bottom corner 96. Thus, it can be appreciated FIG. 4 that the tapeassembly 10 must be constructed so that the holding member 126 and thefront wall portion 200 cooperate to allow the fastener 58 to bepositioned upwardly relative to the housing assembly 12 sufficiently toallow the housing opening 22 to have the height as aforesaid. Theheights of prior art housing openings are generally restricted by theposition of a fastener over the housing opening. Prior art housingassembly construction prevented the fastener from being spaced upwardlyfar enough to provide an opening having a height dimension large enoughto protect the hook member from impact damage as aforesaid. The presentinvention overcomes this problem by constructing the lower front wallportion 200 of the housing assembly so that it is essentially flush withthe central portion 204 of the front of the housing assembly. Bypositioning the lower front wall portion 200 essentially flush with thecentral front wall portion 204, the associated axially extendingfastener 58 can be moved upwardly sufficiently to allow the housingassembly opening 22 to have a height as recited sufficient to protectthe hook member in the event of impact. Specifically, the increasedhousing opening height allows the bottom edge 177 to move upwardly to aposition flush with the bottom surface 170 of the housing assembly 12adjacent the opening 22 before the mounting portion 150 of the hookmember 34 impacts any downwardly facing surfaces on the housing assembly12.

It can be appreciated from FIG. 4 that in the exemplary embodiment ofthe tape assembly 10, the interior free end 128 of the holding member126 is disposed generally above the mounting portion 150 of the hookmember 34 when the hook member 34 is at the opening 22. The recess 129is provided in the free end 128 of the holding member 126 so that if thehook member 34 is caused to move upwardly in the opening 22 because ofan impact, the free end 128 of the holding member 126 does not preventupward movement of the hook member 34 in the opening 22 so that thebottom edge 177 can move upwardly to a position flush with exteriorhousing assembly 12 bottom end surface 170. More particularly, thecentral recess 129 is of a width to operatively accommodate the width ofthe hook member mounting portion 150. Therefore when the hook member 34is forced upwardly in housing opening 22 by an impact, the mountingportion 150 moves upwardly into the recess 129, thereby allowing thebottom edge 177 of the hook member 34 to move upwardly sufficiently sothat it is flush with the bottom end surface 170 of the housing assemblyadjacent the opening 22. If the recess 129 were not provided, the freeend 128 of the holding member 126 could possibly restrict the upwardmovement of the mounting portion 150 so that an impact on the hookportion 152 of the holding member 34 could bend of the hook member 34against the holding member 126. The recess 129 precludes the possibilityof this type of damage to the hook member 34 by allowing the holdingmember 34 to move upwardly in the housing assembly opening 22 at leastfar enough to allow the bottom edge 177 to move flush with the surface170 at the bottom end of the housing assembly 12.

The opening 22 is constructed to allow the hook member 34 to moveupwardly in the opening 22 until the upper edges of the mounting portion150 impacts structure at the top of the opening 22. More specifically,it can be appreciated from FIGS. 4 and 11 that the lateral edges of themounting portion 150 adjacent the hook portion 152 provide upwardlyfacing surfaces 206 which engage one or more downwardly facing surfaces208 defining the housing opening 22 to limit the upward movement of thehook member 34 within the opening 22. The lateral longitudinallyextending edges 210 of the blade 16 extend upwardly and outwardly beyondthe upwardly facing surfaces 206 of the hook member mounting portion150, but the edges 210 do not limit the upward movement of the hookmember 34 in the opening 22. This is because when the hook member 34moves upwardly in the opening 22 during impact, the edges 210 of theblade 16 engage the downwardly facing housing opening surfaces 208 anddeflect resiliently outwardly before the mounting portion 150 of thehook member 34 engages of the upwardly facing surfaces 206. In otherwords, in the exemplary embodiment of the tape assembly 10 shown, theconcavo-convex cross sectional curve height of the blade 16 is such thatthe edges 210 are normally above the upwardly facing surfaces 206 on themounting structure 150 of the hook member 34. When the hook member 34 atthe opening 20 is moved upwardly with respect to the housing assemblyopening 22 by an impact, the edges 210 of the blade 16 impact the upperportion of the opening 22 first, causing the edges 210 of the blade toflex outwardly in opposite directions, slightly flattening the blade 16to a degree sufficient to allow the mounting portion 150 of the hookmember 34 to move toward and into contact with the downwardly facingsurfaces 208 at housing opening 22. When the upwardly facing surfaces206 on a mounting portion abut the downwardly facing surfaces 208 at theopening 22, the hook member 34 reaches the upper limiting position ofits upward movement in the housing opening. This upper limiting positionis usually not reached, however, because preferably the tape assembly 10is constructed and arranged such that the bottom edge 177 of the hookmember 34 moves upwardly to a position flush with the surface 170 on thebottom of the housing assembly 12 before the upwardly facing surfaces206 on the hook member 34 impact the downwardly facing surfaces 208 onthe housing assembly 12. When the bottom end 177 of the hook member 34is flush with the bottom end surface 170 of the housing assembly, thehook member 34 is protected with further impact, thereby preventingdamage to the hook member 34.

It can be understood that the coiled blade 16 has a tendency to unwindand return to a straight (in the longitudinal direction), extendedconfiguration of concavo-convex cross-section. This tendency provides adownward force on the free end 20 of the fully retracted blade 16 withrespect to the housing assembly opening 22 that maintains the extendedportion of the fully retracted blade 16 against the bottom of thehousing assembly interior at the opening 22 and thereby normallymaintains a portion of the hook member 34 of the fully retracted blade16 below the bottom surface 170 of the exterior of the housing assembly12. This allows the tape assembly user to easily hook the hook member 34on a structure such as a workpiece because a portion of the hook member34 is normally below the surface 170.

One skilled in the art will understand that the embodiment of the taperule assembly 10 shown in the figures and described above is exemplaryonly and not intended to be limiting. It is within the scope of theinvention to provide any known tape rule assembly with any or all of thefeatures of the present invention. For example, the clear film ofplastic material can be applied to any known tape rule assembly.Similarly, an end hook member constructed according to the principles ofthe present invention can be applied to any known rule assembly.

The features of the housing assembly including the molded plasticconstruction, the shape of the housing, the use of relatively few bolts,the elimination of bolts in the upper portion of the housing assembly,the manner in which the spindle is mounted therein, the height dimensionof the housing assembly opening relative to the dimension of thedownwardly extending portion of the hook member on the free end of theblade and construction of the finger engaging portion on the bottomsurface of housing assembly can be used separately or in combination onany existing tape rule assembly.

Similarly, the geometry of the cross-section of the blade and thegeneral teachings of the dimensions and construction of the blade andcoil spring can be used on any existing tape rule assembly.

The construction of the fitment, including the construction of thetangentially extending transversely spaced elongated ridges thereof canbe used on any known tape rule assembly. It can also be understood thateven though it is preferable to construct the tape rule assembly havingthe ridges on a separate fitment, it is contemplated to provide anembodiment of the tape rule assembly in which the ridges are formedintegrally on the housing members of the housing assembly. It can alsobe appreciated that it is contemplated to use any of the aforementionedfeatures singly or in any appropriate combination on a tape ruleassembly that has a spring-powered retractable blade or, alternatively,on any tape rule assembly in which the blade is manually retracted.

It can be appreciated by one skilled in the art that it is within thescope of the present invention to apply the teachings presented hereinto construct a tape measure of a wide range of sizes and that it is notintended to limit the invention to the embodiments or to the specificmeasurements or ranges of measurements presented herein. It can beunderstood, for example, that it is within the scope of the invention toconstruct a retractable tape measure assembly that includes a one inchwide (i.e., flattened width) tape blade with increased standout. Becauseit is contemplated to provide tape measure assemblies with the featuresof the invention enumerated herein separately or in any combination, itcan be understood that a wide range of tape measure assemblies havingone inch wide blades could be constructed. More specifically, a tapemeasure assembly having one inch wide blade could include for example, across-section blade geometry; a small footprint housing; a hook member;a protective film; a housing opening height and hook member size; and/ora fitment with transversely extending ribs all as described above in anycombination.

It will thus be seen that the objects of the present invention have beenfully and effectively accomplished. It will be realized, however, thatthe foregoing specific embodiments have been shown and described for thepurposes of illustrating the functional and structural principles of thepresent invention and is subject to change without departure from suchprinciples. Therefore, this invention includes all modificationsencompassed within the spirit and scope of the following claims.

What is claimed is:
 1. A retractable rule assembly comprising a housingassembly; a reel rotatably mounted in said housing assembly; anelongated blade formed of a ribbon of metal having one end connected tosaid reel constructed and arranged with respect to said housing assemblyto extend from a position tangential to said reel outwardly through aspaced opening in said housing assembly; said blade having a hook memberon the free end thereof, said hook member including a hook portion and amounting portion extending generally perpendicular from said hookportion connected with the free end of the blade for limited relativemovement along said blade in an amount generally equal to thickness ofsaid hook portion, a coil spring formed of a ribbon of metal having aconstruction and arrangement between said housing assembly and said reelto rotate said reel in said housing assembly in a direction to wind upthe elongated blade when extending outwardly of said housing assemblyopening in a normal concavo-convex cross-sectional configuration ontosaid reel in an abutting volute coil formation in a flattenedcross-sectional configuration; and a blade holding assembly constructedand arranged to be manually actuated to hold the blade in any positionof extension outwardly of said housing assembly opening and to releasethe blade from any position in which it is held; wherein the metalribbon of said spring has a width which is 95%-120% of the width of themetal ribbon of said blade.
 2. A retractable rule assembly as defined inclaim 1 wherein said housing assembly includes a pair of cooperatinghousing members, each including an end wall having a peripheral wallextending from a periphery thereof and terminating in a free edge, saidhousing members being fixed together with their free edges interengagedby a plurality of bolts extending through one of said housing membersand threadedly engaged in the other at spaced positions adjacent theperipheral walls thereof and by a fixed reel spindle having anon-circular interengaging recess-projection connection at each endthereof with the central interior of the adjacent end wall, each end ofsaid spindle being interiorly threaded to threadedly receive a bolttherein extending through a central hole in the adjacent end wall andthe recess-projection connection between the central hole and threadedinterior.
 3. A retractable rule assembly as defined in claim 2 whereinsaid housing assembly includes only two corner portions, one adjacentsaid housing assembly opening and the other at an opposite bottom endthereof, said plurality of bolts including only two bolts positioned insaid only two corner portions.
 4. A retractable rule assembly as definedin claim 3 wherein said housing members are include portions along theabutting free edges thereof of tongue and groove construction.
 5. Aretractable rule assembly as defined in claim 4 wherein said housingmembers and said spindle are constructed of a molded plastic.
 6. Aretractable rule assembly as defined in claim 5 wherein said housingassembly including a bottom wall having an exterior portion at an endposition adjacent the housing assembly opening which projects below theexterior surface portion extending therefrom toward an opposite end toprovide a finger grip enhancing configuration.
 7. A retractable ruleassembly as defined in claim 6 wherein said hook portion is constructedand arranged to extend downwardly below a bottom surface of said housingassembly when at said housing opening and wherein said housing openinghas a height dimension which exceeds the height dimension of said hookmember mounting portion and its connection with the free end of saidblade an amount which is at least approximately equal to the amount saidhook portion extends below said bottom end surface of said housingassembly when at said housing opening and wherein said locking memberincludes a blade engaging and locking free end portion, said lockingfree end portion including a central recess of a width to operativelyaccommodate the width of said hook member mounting portion.
 8. Aretractable rule assembly as defined in claim 7 wherein said housingassembly includes a fitment defining a part of the housing assemblyopening adjacent a convex side of said blade, said fitment having aplurality of tangentially extending transversely spaced elongated ridgesdefining surfaces for engaging the convex side of said blade extendingtangentially from said reel to said housing assembly opening.
 9. Aretractable rule assembly as defined in claim 8 wherein the thickness ofthe metal ribbon of said spring is 0%-25% thinner than the thickness ofthe metal ribbon of the blade.
 10. A retractable rule assembly asdefined in claim 9 wherein said holding assembly includes a holdingmember mounted on said housing assembly for arcuate movement in oppositedirections between a normally inoperative position and a holdingposition, said holding member having (1) said free end movable intowedging engagement with the tangentially extending portion of said bladeto hold the same against an interior holding surface in the housingassembly when said holding member is in said holding position and (2) anexterior thumb engaging portion configured to be moved digitally to movesaid holding member from the normally operative position thereof to theholding position thereof.
 11. A retractable rule assembly as defined inclaim 10 wherein the height of the housing assembly does notsubstantially exceed 3.65 inches for a blade length that is at mostapproximately 33 feet, wherein the height of the housing assembly doesnot substantially exceed 3.45 inches for a blade length that is at mostapproximately 30 feet, and wherein the height of the housing assemblydoes not substantially exceed 3.25 inches for a blade length that is atmost approximately 8 meters.
 12. A retractable rule assembly as definedin claim 11 wherein the metal ribbon of said spring is 100%-110% of thewidth of the metal ribbon of the blade.
 13. A retractable rule assemblyas defined in claim 3 wherein said housing assembly including a bottomwall having an exterior portion at an end position adjacent the housingassembly opening which projects below the exterior surface portionextending therefrom toward an opposite end to provide a finger gripenhancing configuration.
 14. A retractable rule assembly as defined inclaim 13 wherein a top surface of said housing assembly is arcuate tosubstantially conform to the upper portion of the reel and to provide anarcuate top surface that is constructed and arranged such that agripping hand can hold the housing assembly with a palm and a thumb ofthe gripping hand on the arcuate top surface and with fingers of thehand disposed on the portion of said bottom wall of said housingassembly that provides said finger grip enhancing configuration.
 15. Aretractable rule assembly as defined in claim 14 wherein said holdingassembly includes a holding member mounted on said housing assembly forarcuate movement in opposite directions between a normally inoperativeposition and a holding position, said holding member having (1) aninterior free end movable into wedging engagement with the tangentiallyextending portion of said blade to hold the same against an interiorholding surface in the housing assembly when said holding member is insaid holding position and (2) an exterior thumb engaging portionconfigured to be moved digitally to move said holding member from thenormally operative position thereof to the holding position thereof,said interior free end portion including a central recess of a width tooperatively accommodate the width of said mounting portion of said hookmember.
 16. A retractable rule assembly as defined in claim 15 whereinthe height of the housing assembly does not substantially exceed 3.65inches for a blade length that is at most approximately 33 feet, whereinthe height of the housing assembly does not substantially exceed 3.45inches for a blade length that is at most approximately 30 feet, andwherein the height of the housing assembly does not substantially exceed3.25 inches for a blade length that is at most approximately 8 meters.17. A retractable rule assembly as defined in claim 16 wherein the metalribbon of said spring is 100%-110% of the width of the metal ribbon ofthe blade.
 18. A retractable rule assembly as defined in claim 17wherein said hook portion is constructed and arranged to extenddownwardly below a bottom surface of said housing assembly when at saidhousing opening and wherein said housing opening has a height dimensionwhich exceeds the height dimension of said hook member mounting portionand its connection with the free end of said blade an amount which is atleast approximately equal to the amount said hook portion extends belowsaid bottom end surface of said housing assembly when at said housingopening and wherein said locking member includes a blade engaging andlocking free end portion, said locking free end portion including acentral recess of a width to operatively accommodate the width of saidhook member mounting portion.